Advanced Add-on Armor
for
Light Vehicles

A combination of passive and reactive armor was
introduced in the 1980s, as more advanced armor solutions
were implemented with upgraded and new platforms, such as
Leopard-2A6 (above), Challenger 2, Leclerc,
Merkava Mk4, Mk3, and IMI Sabra (modernized
M-60 version developed by IMI for the Turkish Army Tank Upgrade
Program - photo below). Composite armor uses
various materials different hardness and elasticity, heat and
shock absorbing materials, layered and sandwiched together, to
provide improved protection against specific threats, such as
multiple-hits of Kinetic Energy (KE), and Chemical Enegry (CE) ammunition.

Composite passive armor is designed to
absorb the energy of the impact, and prevent penetration and
internal damage by the penetrating projectile or its residual
effects. Active and Reactive protection systems are
designed to detect and deflect an incoming round or destroy it
during the initial phase of the penetration. Deflection of
shaped-charge weapons such as rocket-propelled grenades and
anti-tank missiles without adding extra weight, as did the current
reactive armor system. Composite armor is usually provided in
modules or tiles, which are composed of a mosaic of hard (ceramic)
materials, soft but strong (composite fibers) embedded in concrete
matrixes. The frontal plan is usually covered with softer
material, such as rubber or other composites, which are used to
dissipate the initial impact and minimize the damage to the
internal mosaic, thus retaining its multi-hit protection
capability. Typical passive add-on armor is the
MEXAS, produced by
IBD in Germany. In some models of passive composite armor,
reactive, non energetic materials are contained between the
different layers of the armor. These materials react when hit by a
projectile, and cause the whole module to change its physical
characteristics.

Different
passive protection was developed for amphibious vehicles. In the
1990s, an enhanced appliqué armor kit (EAAK) was developed by
RAFAEL and installed on the USMC Amphibious Assault Vehicles
(AAV7A1). This add-on armor retains the vehicle's floating
capability. More advanced add-on protection suits are based on hybrid modules, such as the IMI-RAFAEL
L-VAS protection suite for the M-113 and LAV/Stryker APCs.
This system is utilizing a hybrid armor
solution, comprising of both passive and reactive armor, added
with mesh traps, to provide front and side multi-hit protection
from RPGs, 14.5mm AP and 155mm shell fragments, at a total weight
increase of only two tons. Mesh traps also known as
Slat Armor are
also deployed on the Stryker Armored Personnel carriers, currently
deployed in Iraq. Within a decade, futuristic concepts
such as the Future Combat Systems armored elements are expected to
field protection systems capable of deflecting large caliber HEAT
(High Explosive Anti-Tank) and kinetic munitions (APFSDS).

For Future Combat
Systems, planned for deployment in the next decade, the US Army is
studying optimized armor configurations, including frontal armor
that will weigh 80lb/ft2 which will be capable of defeating
medium-caliber automatic cannon threats, shaped-charge threats,
and residual threat debris from large-caliber KE intercepted by an
Active Protection Systems (APS). Another type of armor, designed
for light vehicles, will be able to defeat heavy machine gun
threats at 20 lb/ft2. Tests of various candidate designs is
expected in 2004.

Further
in the future, advanced protection techniques are developed,
including stealth, smart armor, which attempts to deflect a round
once it has penetrated the first layer of armor, and
electromagnetic armor, which deforms and reshapes the penetrating
rounds or plasma jet – both methods are causing the projectile's
disintegration inside the armor, by its own kinetic or heat
energy. These technologies are expected to mature in time for FCS
Block II. The US Army is currently testing electromagnetic armor
concepts on the Bradley. The system uses spaced, add-on modular
elements, formed with a charged element and a forward surface,
used as a precursor. the HEAT jet which penetrates the forward
layer discharges the internal layer, and the effect causes the jet
to dissipate and loose its energy. The system can be recharged and
therefore protect the vehicle from multiple shots. The current
version of electromagnetic armor is designed primarily against
relatively small (RPG style) threats, but could be upgraded (with
more power) to protect against larger HEAT warheads. United
Defense, which develops the system under an ARL program, expects
that the concept could mature in a few years, if adequate funding
is made available for the program.